Extra Coarse Coffee Grind used for Cold Brewing methods.
Coarse Coffee Grind most commonly used for French Press coffee.
Medium Coffee Grind used in Drip brewing methods.
Medium-Fine Coffee Grind used for Pourover Cones, Vacuum Pots, and Siphon Brewers.
Fine Coffee Grind used for espresso.
Extra Fine Coffee Grind used for Turkish coffee.
The grind levels presented are estimates.
Experiment in small increments to get the flavour you want.
Espresso will probably be the most crucial, since Espresso is a microcosm of coffee, being under pressure, the smallest change in grind can result in a noticeable outcome in the flavour.
As per the photographs, using a U.S. nickel (21.21mm x 1.95mm) to visually display the degree of grind.